This proposal requests instrumentation for single crystal X-ray diffraction analysis to serve the needs of a group of researchers in the Departments of Chemistry and Biochemistry of Cornell University. The individual projects involve a wide range of biologically significant structures - synthetic intermediates of anticancer compounds, enzyme generated intermediates, models for structure-activity relationships, insect disease compounds, anesthetics, peptides and proteins. The proposed instrumentation would be placed in the Chemistry Department's X-ray Facility where a staff crystallographer will maintain and operate it. The staff crystallgographer will also provide instruction in crystallographic techniques and crystallographic services to the investigators.